New 4.1 build, Starts and runs for 5 seconds then Dies - Need the GN Gods!

[Nero328]

If anyone can help me get this beast running I know it is this board!!!

A little back story - I rebuilt my 4.1 with the equipment in my signature. I got everything put back in the car and buttoned up, turned the key and it runs great for about 5 seconds and then dies, it acts like it runs out of fuel. I am able to force it to run by pedaling the throttle but if I lift off the throttle or hold steady on the throttle it stumbles and dies. I need to update my signature because I also installed 80# injectors from TT and a new TT chip that Eric made for me. I have been at this for a couple of days so let me list what I have checked so far...please forgive me if I forget something because I feel like I have tried everything but it has to be something simple.

1) Fuel Pressure 43 PSI at the rail verified by Autometer in car gauge. It stays solid at 43 PSI when running and doesn't fall when it dies
2) Translator Plus settings - Toggle switches ON,ON,ON,OFF all dials set to 0 (Zero)
3) ECM verified with known working unit
4) NO Vaccum Leaks Detectable
5) Caspers Cam Sensor with LED so I feel pretty confident it is set right
6) Checked adjustment of Crank Sensor
7) New 103 Octane Fuel
8) SES Light blinks once then solid
9) New Plug Wires
10) New Plugs
11) All Grounds on the back of the motor are mounted firmly to the passenger head.
12) O2 Sensor brand new (Caspers Heated sensor)
13) TPS reading .36
14) IAC Reading 140 (Iread that Eric sets them this way for initial startup to reduce startup high idle)
15) BL is 128
16) No Error Codes
17) AF is 04
18) Scanmaster is reading RPM values
19) New Fuel Filter

I am sure there is something I forgot but I will respond to any questions and appreciate any support offered. This TB.Com community is by far the best board I have ever been a part of and I have supreme confidence that we can figure it out together. I am ready to go drive this baby...I bought it as a basket case and haven't been able to sit behind the wheel yet! HELP!

Thanks in advance!

 

[Chuck Leeper]

13) TPS reading .36

Too low.

 

[Nero328]

Too low.

Ok...what should it be?

 

[psycho6cyl]

idk much but theres no codes and the ses light comes up. is the chip all the way in? maybe bent prongs?

 

[earlbrown]

.42

 

[Nero328]

idk much but theres no codes and the ses light comes up. is the chip all the way in? maybe bent prongs?

The chip is in all the way and I have used 2 different ECM's...I haven't actually checked the prongs in both ECM's but I would think it would be rare for both ECM's to have the exact same prongs bent back. I will check that however...good thought.

 

[Nero328]

.42

TPS is now .42 still the same problem.

 

[bison]

Post a log of the stall and leading up to it from the time you start the car


BPE2013@hotmail.com

 

[Jerryl]

KOEO, set scanmaster to AF, press the gas pedal. Does the number change?

 

[Nero328]

Post a log of the stall and leading up to it from the time you start the car


BPE2013@hotmail.com

Unfortunately I don't have that capability (at least I don't think I do) I do not have a power logger nor an old computer to connect to one if I did.

 

[Nero328]

KOEO, set scanmaster to AF, press the gas pedal. Does the number change?

No it doesn't

 

[EVIL]

I had a similar problem a few years ago.
It ended up being the caspers cam sensor cap.
When I'd loosen the screws a bit it ran fine.
I ended up changing it to a factory cap.

It's worth a shot.

D

 

[bison]

I had a similar problem a few years ago.
It ended up being the caspers cam sensor cap.
When I'd loosen the screws a bit it ran fine.
I ended up changing it to a factory cap.

It's worth a shot.

D

If this were true as soon as the car started unplug the cam sensor and the problem should go away


BPE2013@hotmail.com

 

[TurboTdr3.8]

Were the valves adjusted properly , were they new injectors ?

 

[34blazer]

If you can keep the engine running by delta TPS(moving throttle), it seems as only the AE event is keeping the engine running until there is no delta TPS? Seems like a MAF issue to me. What are the LV8 readings if you can keep it running?

 

[TurboDave]

Regretably, this same thing has happened to me a couple times over the last 27 years. One time after installing a new engine, I had forgotten to properly tighten the vacuum block on top the throttle body (massive vacuum leak). The second time I hadn't noticed that I forgot to properly attach the maf to the maf tube to the turbo (another massive pre turbo vacuum leak). Tripple check all your connections.
The only other thing I can think of that match your symptoms could be an anti theft chip activated.

 

[Nero328]

If this were true as soon as the car started unplug the cam sensor and the problem should go away


BPE2013@hotmail.com

I will try this later when I have someone available to start it for me but I can't start it and run round and unplug it before it dies.

 

[Nero328]

Were the valves adjusted properly , were they new injectors ?

Brand new injectors...the valves were adjusted to Zero lash plus one half turn as suggested by Champion when I spoke to him.

 

[Nero328]

If you can keep the engine running by delta TPS(moving throttle), it seems as only the AE event is keeping the engine running until there is no delta TPS? Seems like a MAF issue to me. What are the LV8 readings if you can keep it running?

I will have to check this in a little while too. I suspect a MAF a problem as well but short of replacing everything I don't know how to diagnose it. When unplugging the MAF It does the exact same thing.

 

[Nero328]

Regretably, this same thing has happened to me a couple times over the last 27 years. One time after installing a new engine, I had forgotten to properly tighten the vacuum block on top the throttle body (massive vacuum leak). The second time I hadn't noticed that I forgot to properly attach the maf to the maf tube to the turbo (another massive pre turbo vacuum leak). Tripple check all your connections.


The only other thing I can think of that match your symptoms could be an anti theft chip activated.

I am told that the TT chips do not have anti theft unless you request it and I certainly didn't request it. It's hard enough keeping these things running without having to worry about something like that giving me fits and diagnosing heartburn!

As for the Vaccum leaks, I have checked every single connections multiple times and haven't found anything. I would think that even with a vacuum leak it would try to idle or at least seak around for the right fuel mixture but it's not doing that at all...it simply falls flat on its face.